At least one-fifth of men inside state prisons have mental health problems, over half have experienced physical, sexual, or emotional abuse (referred to as interpersonal trauma) during their formative years and often in adulthood, and the majority has alcohol or drug use problems. Interpersonal trauma is highly correlated with health and behavioral health problems and criminality. Few male inmates receive treatment for behavioral health disorders related to interpersonal trauma while incarcerated even though these problems are risk factors for returning to prison after release. While the Surgeon General's Report and the President's New Freedom Commission Report highlighted the importance of trauma-informed services and systems of care, trauma- related behavioral health problems among incarcerated men have received little attention. This application addresses both screening for and treatment of Post-Traumatic Stress Disorder (PTSD) and substance use disorders (SUD) within an adult male correctional setting. The proposed study will be conducted at an adult medium security prison in New Jersey that houses ~1900 male inmates primarily aged 18 to 25. We propose a two-phase study that: (1) tests the reliability (test-retest) of computer-administered screening for PTSD and SUD compared to clinician-administered screening (goal: to develop a cost-effective population- based screening procedure for PTSD and SUD within incarcerated settings) and (2) conduct a randomized controlled trial (RCT) in which 240 male inmates are assigned to two evidence-based, manualized first stage trauma interventions (Seeking Safety (SS) and Trauma Recovery and Empowerment Model version for men with substance use problems (M-TREM) (goal: to identify effective interventions for PTSD and SUD among incarcerated men). The RCT will be enhanced in two ways: (1) those who decline treatment participation will be shown a 10-minute educational video on PTSD and SUD and after viewing the video invited a second time to participate in the RCT and (2) determined by random assignment, two-thirds of participating subjects (n=160) will be randomly assigned to treatment and the other one-third (n=80) will choose treatment based on their preference for one intervention over the other. We will be testing overall effectiveness of screening and treatment interventions and the marginal impact of educational-enhancement and preferences on outcomes.